The leader of a Ukrainian separatist rebel group backed by Russia was killed in an explosion Friday along with his bodyguard, and at least 12 others were wounded, the health minister of Ukraine’s splinter Donetsk region said Saturday.

Alexander Zakharchenko, 42, the separatist leader of the self-proclaimed Donetsk People’s Republic, died as a result of the explosion at a café in the eastern city of Donetsk, the Interfax Russian news service reported Friday. The official rebel news agency confirmed the death.

Under the title of prime minister, Zakharchenko headed the breakaway Ukrainian region that has been at the center of an ongoing war between Ukrainian government troops and Kremlin-backed separatist militias.

“Unfortunately, the head of the Donetsk People’s Republic, Alexander Zakharchenko, has died as a result of the terrorist act,” Donetsk News Agency, the rebel media website, said, quoting a statement from the administration of the rebel government.

Advertisement

On Friday it had been reported that one other person was killed in the blast, and on Saturday, Alexander Oprishchenko, health minister in the breakaway province that has declared itself a republic, announced the death of the bodyguard, who was not named, and that 12 others were wounded. The severity of their injuries was not released.

It was reported on Friday that the separatist government’s tax minister was among the injured.

On Saturday, the Associated Press reported that the killings have led to increased tensions and worry by separatists that Urkraine is preparing to launch a new offensive against the rebels.

The explosion took place in the late afternoon at a cafe called Separatist in Donetsk’s central, tree-lined Pushkin Boulevard, Russian media reported. The boulevard is popular for strolling and is dotted with outdoor cafes and restaurants during the summer.

Advertisement

Zakharchenko rose to power in the separatist militia first as a commander in the early days of the Moscow-supported rebels’ fight against Ukraine’s government forces in 2014. The separatists declared their own republic in the industrialized and coal-rich eastern Ukrainian regions of Donetsk and Luhansk in March 2014. The events followed a popular street movement in the Ukrainian capital of Kiev that led to the ouster of a Moscow-favored president and Russia’s annexation of Crimea in February 2014.

Ukrainian government troops have been fighting the separatist troops, who are aided and supported by the Kremlin, in a four-year war that has claimed more than 10,000 lives and displaced 1.2 million Ukrainians. The Kremlin has denied sending troops to support the rebel militias and claims the fighting is a civil war that erupted after an illegal power grab in Kiev. The separatist governments said they want independence from Ukraine and closer ties with Russia, while the Ukrainian government has signed an association and trade agreement with the European Union.

The United States has sent military trainers to support the Ukrainian government troops and supplied them with anti-tank missiles, a move that has irritated Russia.

Zakharchenko, a former mining engineer, was elected prime minister of the rebel government in November 2014. He later became the rebel territory’s representative in the Minsk peace talks, an ongoing peace negotiation involving Russia, several European nations, Ukraine and the rebel-held territories. The talks have failed to resolve the ongoing conflict in eastern Ukraine, and international observers from the Organization for Security and Cooperation in Europe report weekly ceasefire violations on both sides of the conflict line.

The law enforcement agencies in the rebel territory said they had detained “Ukrainian saboteurs” suspected in Zakharchenko’s assassination, Interfax reported a source from the rebel government as saying.